Re: [PATCH v2] Cygwin: console: Abort read() on signal if SA_RESTART is not set.

[Takashi Yano <takashi.yano@nifty.ne.jp>]

On Mon, 15 Feb 2021 13:04:41 +0100
Corinna Vinschen wrote:
> On Feb 14 18:42, Takashi Yano via Cygwin-patches wrote:
> > - Currently, console read() keeps reading after SIGWINCH is sent
> >   even if SA_RESTART flag is not set. With this patch, read()
> >   returns EINTR on SIGWINCH if SA_RESTART flag is not set.
> >   The same problem for SIGQUIT and SIGTSTP has also been fixed.
> > ---
> >  winsup/cygwin/fhandler_console.cc | 7 +++----
> >  winsup/cygwin/fhandler_termios.cc | 1 +
> >  winsup/cygwin/tty.cc              | 1 +
> >  winsup/cygwin/tty.h               | 1 +
> >  4 files changed, 6 insertions(+), 4 deletions(-)
> > 
> > diff --git a/winsup/cygwin/fhandler_console.cc b/winsup/cygwin/fhandler_console.cc
> > index 3c0783575..78af6cf2b 100644
> > --- a/winsup/cygwin/fhandler_console.cc
> > +++ b/winsup/cygwin/fhandler_console.cc
> > @@ -586,12 +586,11 @@ wait_retry:
> >  	case input_ok: /* input ready */
> >  	  break;
> >  	case input_signalled: /* signalled */
> > -	  release_input_mutex ();
> > -	  /* The signal will be handled by cygwait() above. */
> > -	  continue;
> >  	case input_winch:
> >  	  release_input_mutex ();
> > -	  continue;
> > +	  if (global_sigs[get_ttyp ()->last_sig].sa_flags & SA_RESTART)
> 
> Shouldn't this check for last_sig != 0 first?

This code is reached only after SIGINT, SIGTSTP, SIGQUIT (case
input_signalled) or SIGWINCH (case input_winch) has been sent.
Therefore, last_sig should be one of them here.

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>